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In a solution, which pair of actions could combine to keep a concentration constant?(1 point) Responses adding solute, then removing solution adding solute, then removing solution adding solute, then evaporating water adding solute, then evaporating water adding water, then adding solute adding water, then adding solute adding water, then removing solution adding water, then removing solution Remaining Attempts : 3

11 answers

To keep a concentration constant in a solution, one effective pair of actions would be adding water, then adding solute. This maintains the ratio of solute to solvent (concentration) at a constant level, as the increase in both components keeps the ratio the same.

So, the correct answer is: adding water, then adding solute.

A substance has a pH of 8.0. How would it be classified?(1 point) Responses weak base weak base strong acid strong acid weak acid weak acid strong base strong base Remaining Attempts : 3

A substance with a pH of 8.0 would be classified as a weak base. In general, a pH above 7 indicates a basic solution, with weak bases typically falling within the pH range of approximately 7 to 10. Strong bases usually have a pH of 12 or higher. Thus, the correct response is weak base.

vThe same quantity of each solute is added to water. Which solution will have the greatest number of H3O+ ions at equilibrium? (1 point) Responses strong base strong base - no response given weak acid weak acid - no response given strong acid strong acid - no response given weak base weak base - incorrect Incorrect Bases attract hydrogen ions from water. Remaining Attempts : 1

At equilibrium, the solution that will have the greatest number of \( \text{H}_3\text{O}^+ \) ions will be the strong acid.

Strong acids dissociate completely in water, producing a high concentration of \( \text{H}_3\text{O}^+ \) ions. Weak acids only partially dissociate, resulting in fewer \( \text{H}_3\text{O}^+ \) ions compared to strong acids. Similarly, bases, whether weak or strong, will lower the concentration of \( \text{H}_3\text{O}^+ \) ions.

Thus, the correct choice is strong acid.

The element phosphorous (P) has an atomic number of 15 and an atomic mass of 31. How many neutrons are in an atom of phosphorous (P)?(1 point) Responses 15 15 16 16 31 31 46 46 Remaining Attempts : 3

To find the number of neutrons in an atom of phosphorus (P), you can use the formula:

\[ \text{Number of Neutrons} = \text{Atomic Mass} - \text{Atomic Number} \]

For phosphorus:

  • Atomic Mass = 31
  • Atomic Number = 15

So,

\[ \text{Number of Neutrons} = 31 - 15 = 16 \]

Therefore, the number of neutrons in an atom of phosphorus is 16.

How many electrons are shared in a double bond? (1 point) Responses 2 electrons 2 electrons 6 electrons 6 electrons 4 atoms 4 atoms 1 electron

In a double bond, a total of 4 electrons are shared between two atoms. This is because a double bond consists of two pairs of shared electrons.

Therefore, the correct response is 4 electrons.

What quality do all of the elements in group 18, the noble gases, share?(1 point) Responses They all have the same number of protons in their nucleus. They all have the same number of protons in their nucleus. They all have a full outer valence shell. They all have a full outer valence shell. They all have 8 valence elections. They all have 8 valence elections. They are all highly reactive.

The quality that all of the elements in group 18, the noble gases, share is that they all have a full outer valence shell. This full outer shell is what makes them generally very stable and unreactive compared to other elements.

So, the correct response is: They all have a full outer valence shell.